Exporting to FBX OBJ DAE 3DS
This worked for me:
I packed and unpacked the blender file created, corrected allocation and exported materials from cycles into the .OBJ file. I exported from blender to 3dxchange, and the .OBJ file back into blender. The file retained the correct materials. As long as you create the textures in the same directory when you unpack the file, it seems to work.

When exporting alpha YAY, it took me a while to find this solution and it turned out to be simple.